1. Field
The present invention relates to a display device, and particularly to, a display device including a sealant.
2. Description of the Related Art
A display device, such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, and an electrophoretic display, includes a field generating electrode and an electro-optical active layer. For example, the OLED display includes an organic emission layer as an electro-optical active layer. The field generating electrode may be connected to a switching element, such as a thin film transistor, to receive a data signal, and the electro-optical active layer converts the data signal into an optical signal to display an image.
The OLED display among the display devices is a self-emission type and does not require a separate light source. Thus, the OLED display is advantageous regarding power consumption and has an excellent response speed, viewing angle, and contrast ratio.
The OLED display may include a plurality of pixels, such as a red pixel, a blue pixel, a green pixel, and a white pixel, and may express full colors by combining the lights emitted by the pixels. Each pixel includes an organic light emitting element and a plurality of thin film transistors for driving the organic light emitting element.
The light emitting element of the OLED display includes a pixel electrode, an opposing electrode and an emission layer positioned between the pixel electrode and the opposing electrode. One electrode between the pixel electrode and the opposing electrode is an anode electrode and the other electrode is a cathode electrode. Electrons injected from the cathode electrode and holes injected from the cathode electrode are combined in the emission layer to form excitons, and the excitons emit light while emitting energy. The opposing electrode may be formed over the plurality of pixels and may transmit a predetermined common voltage.
The display device such as the OLED display, may have a problem in that when impurities, such as moisture or oxygen, flow into the display device from a surrounding environment, a lifespan of the device may be decreased due to oxidation and peeling of the electrode, light emission efficiency may deteriorate, and/or a color of light emission may be changed.
Accordingly, a sealing process is performed in order to prevent impurities such as moisture, from permeating by isolating an internal element from the outside when manufacturing the display device. The sealing process includes a method of generally laminating a layer formed of organic polymer, such as polyester (PET) on a completed lower substrate or forming a cover or a cap with an encapsulation substrate, and sealing the edges of the cover or the lower substrate and the encapsulation substrate with a sealant material for the OLED display. A frit having an excellent moistureproofing property may be used as the sealant, and an organic sealant and an absorbent may also be used.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.